1. Field of the Invention
The present invention relates to a solid-state imaging apparatus, and particularly, to a solid-state imaging apparatus and a method of driving the solid-state imaging apparatus including an A/D converting circuit in each column and characterized by applying an arithmetic operation process to obtained plurality of digital signals.
2. Description of the Related Art
So-called horizontal skipping read out (hereinafter synonymous with horizontal skipping operation) is known as an application that requires high-speed operations of moving images in conventional solid-state imaging apparatuses, in which among the pixels arranged in a matrix, an analog electric signal converted from an incident light is read out every other columns in each pixel, for example.
Japanese Patent Application Laid-Open No. 2006-025189 discloses a technique for arranging an A/D converting circuit in each column of pixels and applying an arithmetic operation process to a digitalized signal. Specifically, an image sensor is disclosed in which two register circuits are arranged in each pixel column, two different signal levels of the same pixel are stored, and then an arithmetic operation is performed to the difference of the two in a digital domain.
When a horizontal skipping operation is performed in a circuit configuration as disclosed in Japanese Patent Application Laid-Open No. 2006-025189 and an arithmetic operation is performed with signals held in a plurality of register circuits, A/D converters and register circuits in columns that are skipped, or not read out, are not involved in the operations. A more consideration is needed in terms of the use efficiency of the circuits.